Analysis of biological entities, such as proteins and nucleic acids, in biological samples generally requires that the target entity in question first be isolated from the biological matrix, which frequently includes a complex mixture of non-target substances. The effective isolation of analytes is a prerequisite for efficient downstream analysis of the analyte, including, for example, amplification of a nucleic acid for detection and quantification or identification of a protein or enzyme. It is also important, in many cases, such as in nucleic acid amplification, that the isolated species not contain residues of certain reagents and/or solvents used during isolation.
Existing methods of isolation frequently involve multistep processes, often requiring multiple extraction and/or centrifugation steps, which require trained personnel and can introduce risks of contamination and/or loss of sample. A need exists for a self-contained device that is effective to isolate an analyte from a biological sample, such as obtained from a patient, with minimal operator manipulation of sample and reagents.